Thread carriers for sewing machine loop takers



L. J. KUHAR 2,974,618 THREAD CARRIERS FOR SEWING MACHINE LOOP TAKERS March 14, 1961 Filed Sept. 12, 1958 INVENTOR. Ludwig J. Kuhar Fig.2 BY

WITNESS WWW ATTORNEY THREAD CARRIERS FOR SEWING MACHINE LOOP TAKERS Ludwig J. Kuh'ar, Clark, NJ., assignor to The Singer Manufacturing Company, Elizabeth, NJ., a corporation of New Jersey Filed Sept. 12, 1958, Ser. No. 760,796

2 Claims. (Cl. 112-231) The present invention relates to a thread carrier for the loop taker of a sewing machine and particularly to a thread carrier that is designed to accommodate a centerunwind prewound cop as distinguished from the conventional bobbin. The object of this invention is to provide a simplified latch means for holding the thread case in the thread case carrier, which latch means is inexpensive, easy to operate, dependable, durable, and which will not only serve to latch the thread case securely in the thread case carrier but will also serve as a hand-hold for the thread case when it is removed from the thread case carrier.

Having in mind the above and other objects that will be evident from an understanding of this disclosure, the invention comprises the devices, combinations and arrangements of parts as illustrated in the presently preferred embodiment of the invention which is hereinafter set forth in such detail as to enable those skilled in the art readily to understand the function, operation, construction and advantages of it when read in conjunction with the accompanying drawings in which:

Fig. 1 is a face view in elevation of a sewing machine rotary hook having a thread case carrier and thread case embodying the present invention.

Fig. 2 is a sectional view taken substantially on the line 22 of Fig. 1, showing in dotted lines the latch member opened to release position.

Fig. 3 is a perspective View of the thread case carrier per se.

With reference to the drawings, there is illustrated a sewing machine rotary hook I having a hook body 2 in which is journaled the peripheral bearing rib 3 of a thread case carrier 4. The thread case carrier 4 has a bottom wall 5 and a cylindrical side wall 6 upon the periphery of which is formed the bearing rib 3. Mounted within the thread case carrier 4 is a thread case 7 having a top wall 8 and a cylindrical side wall 9. The space 2,974,618 Patented Mar. 14, 1961 l ce vent insertion of the thread case 7 into the thread case carrier in other than the correct position.

The top wall 8 of the thread case 7 has an upper surface 20 which is planar except for a pair of upstanding lugs 21 and 22 disposed on the edge thereof at diametrically opposite points. The lugs 21 and 22 are undercut to within the side wall 9 constitutes the thread mass receiving cavity in which a thread cop is to be mounted. The

thread case 7 is formed centrally of the top wall 8 with a thread aperture 10 through which the thread lead passes. A thread tension spring 11 is secured to the top wall 8 of the thread case 7 by a fastening screw 12 and a tension adjusting screw 13 with the free end of the spring 11 overlying the aperture 10. A threading slot 14 extends through the side wall 9 and the top wall 8 of the thread case and communicates with the aperture 10.

The thread case carrier 4 has a loop controlling flange 15 extending laterally from the free edge of the side wall 6, which flange is formed with a notch 16 for receiving the rotation restraining finger. On the other side of the flange 15 from the notch 16, the side wall 6 is formed with a needle aperture 17 and inwardly of the aperture 17 there are a pair of rises 18. The thread case 7 is formed with a needle clearance 19 through the top wall 8 and extending through the side wall 9. The clearance 19 is also adapted to cooperate with the rises 18 to preform grooves 23 and are provided with radially extending bores 24 leading from the grooves 23 to the periphery of the. side wall 9. A wire bail 25 is formed with laterally extending free ends 26 that are disposed in the bores 24 and are elongated to extend beyond the periphery of the side wall 9. The inner surface of the side wall 6 of the thread case carrier 4 is provided with a recess, which for manufacturing purposes is formed as a groove 27, that is adapted to receive the ends 26 of the bail 25, the bail 25 being resilient so that the ends 26 are normally biased outwardly.

The bail 25 nonnally lies flat against the upper surface 20 of the thread case, as illustrated in Fig. 1 and in full lines in Fig. 2, with the ends 26 of the bail 25 extending into the groove 27 in the thread case carrier to secure the thread case 7 in the thread case carrier 4. The bail 25 is formed with legs 28 adjacent to the ends 26 which, in this position, are partially received within the grooves 23. To release the thread case 7, the bail 25 is swung upwardly about an axis defined by the ends 26 to the dotted line position of Fig. 2, the thread case 7 and thread case carrier 4 having thumb nail cutaways 29 and 30 respectively to facilitate lifting the bail. The ends of the lugs 21 and 22 are formed with cam faces 31 that cooperate with the legs 28 of the bail to force the ends 26 inwardly out of the grooves 23 as the bail is swung upwardly, thus retracting the ends 26 from the groove 27. The thread case 7 can now be withdrawn from the thread case carrier 4, the bail 25 serving as a finger-hold. When the thread case 7 is replaced in the thread case carrier 4, the bail 25 also serves as a fingerhold. When the bail is swung flat against the upper surface 20 of the thread case 7, the legs 28 are released from the cam edges 31 and are forced outwardly by the resilient action of the bail, thereby spreading the ends 26 and seating the same in the groove 27.

Numerous alterations of' the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to a preferred embodiment of my invention which is for purposes of illustration only and not to be construed as a limitation of the invention. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended claims. 7

Having thus set forth the nature of the invention, what I claim herein is:

1. In a rotary hook for a sewing machine, a thread case carrier having a cylindrical side wall, a thread case adapted to be removably mounted in said thread case carrier and having a top wall and a cylindrical side wall defining a thread mass receiving cavity, and latch means for releasably securing said thread case in said thread case carrier comprising a bail having laterally extending ends, means for mounting said bail on the top wall of said thread case for swinging movement about said ends and for endwise movement of said ends, said bail being resilient and biased to spread said ends for projecting the same beyond the periphery of said thread case, the side wall of' said thread case carrier having means to receive the ends of said ball, and means for retracting the ends of said bail to within the periphery of said thread case when said bail is swung about said ends from a position against said top wall to a position substantially normal to said top wall.

2. In a rotary hook for a sewing machine, a thread case carrier having a cylindrical side wall, a thread case adapted to be removably mounted in said thread case carrier and having a top wall and a cylindrical side wall defining a thread mass receiving cavity, and latch means for releasably securing said thread case in said thread case carrier comprising a bail having laterally extending ends, upstanding lugs upon opposite sides of the top wall of said thread case, said ball having the ends thereof mounted in said lugs for angular and for endwise movement, the ends of said bail being elongated to extend through said lugs beyond the periphery of said thread case, the side wall of said thread case carrier having means to receive the ends of said bail, said bail being resilient to bias the ends thereof outwardly through said 16 2,802,438

lugs, and cam means formed on said upstanding lugs and cooperating with said bail to force the ends inwardly against the resilient action of said bail when said bail is swung upwardly from a position against said top wall to a position substantially normal to said top wall thereby retracting the ends of said bail within the periphery of the thread case carrier.

Relieren ees li ted in the file of this patent UNITED STATES PATENTS 1,471'930 Tmlibfi Oct. 23, 1923 1,981,834 Fleekenstein Nov. 20, 1934 2,379,882 Clark July 10, 1945 Colegrove Aug. 13, 1957 

